Reclosable storage bags are well known, especially with regard to food storage. Such bags are generally made out of a plastic film and have two side walls which are sealed around the edges. Such material is fluid impermeable, relatively inexpensive, and can be manufactured in transparent form thereby facilitating content identification. Accordingly, plastic bags have become the dominant product of choice in the area of food storage bags.
Such bags are typically recloseable and substantially sealable. One common approach to provide such features employs closure members at a top edge of a bag having first and second thermoplastic layers folded or heat sealed along bottom and first and second side edges. The closure members may be provided in the form of mating male and female profiles such as those provided by the present assignee under the ZIPLOC® trademark. The male and female profiles are also typically manufactured from plastic, with the male profile including a linear tab adapted to be interlocked with a linear groove of the female profile.
The male and female profiles can be connected to close the bag by pinching and pulling across the closure members along the length of the top edges. Such motion can be accomplished with the thumb and forefinger of a user, or through the use of a sliding element mounted to the male and female profiles, as is the case with bags provided by the present assignee under the ZIPLOC® trademark as well.
While such bags have been met with extraordinary commercial success from their inception until the present day, the assignee continues to improve its product offerings. One area which the assignee has identified as grounds for improvement involves the ability to evacuate gas from a bag after sealing. While the primary closure found at the top of many plastic bags provides an airtight seal, air remaining enclosed in the bag after closure enables bacterial growth and therefore hinders the preservation and freshness the bags are intended to maintain.
It would therefore be an advance in the art of bags to provide a bag with an evacuation aperture provided with a secondary closure, or valve, for sealing the aperture. In this manner, a bag may be closed at the top using the primary closure member, as described above, and subsequently evacuated of gas and resealed using the aperture and secondary closure, respectively.